The present invention generally relates to improvements in a transesophageal ultrasound probe, and more particularly to a transesophageal ultrasound probe including an expandable scanhead.
Various medical conditions affect internal organs and structures. Efficient diagnosis and treatment of these conditions typically require a physician to directly observe a patient""s internal organs and structures. For example, diagnosis of various heart ailments often requires a cardiologist to directly observe affected areas of a patient""s heart. Instead of more intrusive surgical techniques, ultrasound imaging is often utilized to directly observe images of a patient""s internal organs and structures.
Transesophageal Echocardiography (TEE) is one approach to observing a patient""s heart through the use of an ultrasound transducer. TEE typically includes a probe, a processing unit, and a monitor. The probe is connected to the processing unit which in turn is connected to the monitor. In operation, the processing unit sends a triggering signal to the probe. The probe then emits ultrasonic signals into the patient""s heart. The probe then detects echoes of the previously emitted ultrasonic signals. Then, The probe sends the detected signals to the processing unit which converts the signals into images. The images are then displayed on the monitor. The probe typically includes a semi-flexible endoscope that includes a transducer located near the end of the endoscope.
Typically, during TEE, the endoscope is introduced into the mouth of a patient and positioned in the patient""s esophagus. The endoscope is then positioned so that the transducer is in a position to facilitate heart imaging. That is, the endoscope is positioned so that the heart or other internal structure to be imaged is in the direction of view of the transducer. Typically, the transducer sends ultrasonic signals through the esophageal wall that come into contact with the heart or other internal structures.
The transducer then receives the ultrasonic signals as they bounce back from various points within the internal structures of the patient. The transducer then sends the received signals back through the endoscope typically via wiring. After the signals travel through the endoscope, the signals enter the processing unit typically via wires connecting the endoscope to the processing unit.
In order to obtain accurate images of internal organs and structures, such as the heart, it is preferable that the transducer maintain uniform and close contact with the esophageal wall. The close and uniform contact with the esophageal wall typically assists the transducer to receive signals that are minimally distorted.
FIG. 1 illustrates a conventional transesophageal probe 100 according to one embodiment of the prior art. The conventional probe 100 includes an endoscope 110 and a control handle (not shown). The enodscope 110 includes a scanhead 120 that includes a transducer 130 mounted on the scanhead 120. The transducer 130 includes a direction of view 135. The transducer 130 comes into contact with an esophageal wall 105 of a patient. The control handle and the scanhead 120 are located at opposite ends of the endoscope 110. The transducer 130 is connected to the processing unit via wiring (not shown) that extends through the scanhead 120 and throughout the length of the body of the endoscope 110. The wiring in the conventional probe 100 is then connected via a cable (not shown) to a processing unit (not shown). The processing unit is then connected via wiring to a monitor (not shown) for display of the ultrasound image.
In operation, the scanhead 120 of the probe 100 is introduced into the esophagus of a patient. The probe 100 is then positioned via the control handle so that the internal structure to be imaged is within the direction of view 135 of the transducer 130. The endoscope 110 of the probe 100 is bent in order to gain leverage so that the transducer 130 located on the scanhead 120 may achieve close and uniform contact with the esophageal wall 110. That is, the endoscope 110 is wedged into the esophageal wall 105. Wedging the endoscope 110 into the esophageal wall of the patient may cause discomfort to the patient and/or injure the patient""s esophageal wall. In order to maintain close and uniform contact between the transducer 130 and the esophageal wall 105, the side of the endoscope 110 opposite of the transducer 130 is wedged against one side of the esophageal wall 105 thus pressing the transducer 130 side of the endoscope 110 firmly against the side of the esophageal wall 105 closest to the internal structure being imaged. The transducer 130 then sends ultrasonic signals into the internal structures of the patient and receives the ultrasonic signals that bounce back from the internal structures of the patient. The transducer 130 then sends the ultrasonic signals via wiring through the endoscope 110 to the processing unit. The processing unit then processes and converts the signals into viewable images which are then displayed on the monitor. Once imaging is complete, the endoscope 110 is removed from the patient""s esophagus.
Typically, bending the endoscope 110 and wedging the endoscope 110 into the esophageal wall 105 may not be preferable for several reasons. The bending of the endoscope 110 forces the scanhead 120 to engage the esophageal wall at an angle which may negatively impact the transducer""s 130 ability to image the internal structure. That is, the operative surface of the transducer 130 on the scanhead 120 is not parallel with the esophageal wall. Instead, the transducer 130 is angled into the esophageal wall. Therefore, the transducer 130 typically is not positioned parallel to the surface of the esophageal wall. Typically, the endoscope 110 is positioned so that the direction of view 135 of the transducer 130 is angled below the structure, or at an acute angle. That is, the direction of view 135 is not at a 90xc2x0 angle with respect to the structure being imaged. When the direction of view 135 of the transducer 130 is not at a 90xc2x0 angle with respect to the internal structure being imaged, the image may be distorted due to misleading transducer recordings. That is, the transducer 130 receives signals that bounce back off internal structures that may be at different distances from the transducer 130 if the direction of view 135 was at a 90xc2x0 with respect to the internal structure. Thus, because the transducer 130 is not parallel and in contact with the esophageal wall 105, the transducer 130 may receive a distorted image.
That is, because the scanhead 120 is angled into the esophageal wall 105, the transducer 130 is typically in partial contact with the esophageal wall. Thus, only the portion of transducer 130 contacting the esophageal wall 105 sends signals to, and receives signals from the internal structure being imaged. The partial contact between the transducer 130 and the esophageal wall 105 typically results in the transducer 130 sending and receiving signals with a low amplification. Consequently, the images generated from the received signals are typically incomplete, attenuated, and/or distorted. Typically, incomplete, attenuated, and/or distorted signals are undesirable for accurate medical diagnosis because the image itself is not an accurate portrayal of the internal structure being imaged.
Further, the direction of view 135 of the transducer 130 may cause the endoscope 110 to be mistakenly positioned due to counter-intuitive images displayed on the monitor. That is, the endoscope 110 is positioned via a control handle located on the probe. The control handle is located at the opposite end of the endoscope 110 as the transducer 130. The endoscope 110 is deflected and bent via the control handle of the probe so that the transducer 130 is tilted upward. Because the transducer 130 is located at the distal end of the endoscope 110, the transducer 130 is titled upward as the endoscope 110 wedges against the esophageal wall 105. Because the transducer 130 images the internal structure from below, the corresponding image sent to the monitor is typically counter-intuitive and can potentially cause confusion to an operator observing the image.
Bending the end of the endoscope 110 so that the transducer 130 is pressed against the esophageal wall 105 of a patient may present various physiological problems as well. For example, moving the bent endoscope 110 further down the esophagus may damage the esophageal wall. That is, because the endoscope 110 is wedged into the esophageal wall 105, the distal end of the endoscope 110 is also wedged into the esophageal wall 105. The distal end of the endoscope 110 may snag the esophageal wall 105 and dig into it thereby damaging the esophageal wall 135.
Further, the force to maintain close and uniform contact between the transducer 130 and the esophageal wall 105 may cause wounds to the esophageal wall 105. That is, because the endoscope 110 is deflected and the transducer 130 is pressed against the esophageal wall 105, the force required to maintain close contact with the esophageal wall 105 may be enough force to lacerate, bruise, or otherwise injure the esophageal wall 105.
Therefore, a need has existed for a transesophageal probe that safely, efficiently and accurately images internal organs and structures. Further, a need has existed for an a transesophageal probe that minimizes the susceptibility of injury to the esophageal wall during procedures such as TEE. A need has also existed for a transesophageal probe that requires less force to. maintain a close and uniform contact between the transducer and the esophageal wall.
An internal imaging probe including an expandable scanhead for improving the positioning of an imaging element mounted on the scanhead. The imaging probe is introduced into the esophagus of a patient via the patient""s mouth. Once, the imaging probe is introduced, the imaging probe is positioned to a point where an internal structure of the patient is within the direction of view of an imaging element, such as a transducer, located on the scanhead. Once positioned, the scanhead is expanded. The scanhead may be expanded via inflation, or through the use of a movable extensor located within the scanhead. The inflatable scanhead includes a flexible pouch that receives fluid, such as air or water, from an inflation duct. The scanhead is expanded via engaging a control handle at the proximal end of the imaging probe. Alternatively, the scanhead may be expanded via a moving extensor located within the scanhead. The extensor may be a rotating extensor or a piston-driven extensor.
The scanhead is expanded until the imaging element, such as a transducer, achieves close and uniform contact with the esophageal wall of the patient. Close and uniform contact between the imaging element and the esophageal wall increases the accuracy of the signals received by the imaging element. Further, expanding the scanhead while the scanhead is within the esophagus of the patient minimizes the risks of damage to the esophageal wall that are associated with prior art probes. Once the imaging process is complete, the imaging probe is returned to its unexpanded size and removed from the esophagus of the patient. The imaging probe may be included within a medical imaging system that includes the probe, a processing unit, and a monitor for displaying images of the internal structure.